This invention relates to resurfacing the worn interior walls of a flask cope or drag frame which is used in sand casting molten metal. A typical foundry metal casting flask is formed of an upper, cope frame and a lower, drag frame which are aligned, one above the other, and filled with sand within which a molten metal casting cavity is formed. The sand packed within the boxed-like frames contacts the interior wall surfaces of the cope and drag.
After a period of use, the cope and drag frame interior surfaces become worn and uneven. Such wear is particularly found where a single flask is used repeatedly to make sand cakes for flask-less molds. That is, in that system of casting, sand is packed within a flask cope and drag around a pattern positioned within the frames. The frames are separated vertically and the pattern is removed, following which the frames are realigned one upon the other.
Subsequently, the flask is removed from the packed sand mold or cake. The flask is immediately reused for forming the next sand mold or cake. Meanwhile, the finished sand mold is removed, without the flask, and molten metal is poured into its cavity for casting a metal object therein.
The removal of the flask from the packed sand abrades the interior wall surfaces of the flask frames which causes wear and unevenness. That unevenness can cause the exterior surface of the packed sand mold to stick to, or to interlock with crevices or scratches upon, the worn flask inner surfaces that damage the sand mold and make it more difficult to separate from the flask. Thus, it is desirable to maintain the interior wall surfaces of the flask cope and drag frames in a relatively smooth, unscratched and undamaged condition.
In the present practice, when the interior walls of a flask cope or drag frame become damaged or worn, the flask must be completely replaced or, alternatively, the inner surfaces must be machined flat and smooth if possible. Either choice is relatively expensive and time consuming. Where the flask is replaced entirely, the purchase of an expensive, new flask is necessary. Thus, this invention is concerned with a system for resurfacing the interior worn faces of cope and drag frame.